On Mon, Nov 29, 2010 at 10:03:22AM -0500, Eric Brunner-Williams wrote: > there exist rules, much earlier than 1123, about "-" as the initial, or
Yes. They're the hostname rules. RFC 1035 has this to say about them, in section 2.3.1: The DNS specifications attempt to be as general as possible in the rules for constructing domain names. The idea is that the name of any existing object can be expressed as a domain name with minimal changes. However, when assigning a domain name for an object, the prudent user will select a name which satisfies both the rules of the domain system and any existing rules for the object, whether these rules are published or implied by existing programs. For example, when naming a mail domain, the user should satisfy both the rules of this memo and those in RFC-822. When creating a new host name, the old rules for HOSTS.TXT should be followed. This avoids problems when old software is converted to use domain names. The following syntax will result in fewer problems with many applications that use domain names (e.g., mail, TELNET). [. . . ] The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen. There are also some restrictions on the length. Labels must be 63 characters or less. Now, we have considerable discussion in the first part of that passage that explains why the restrictions that are being introduced are so introduced, despite the fact that the protocol itself happens not to have such restrictions. So, are those rules "merely" allocation policy, or not? I can't tell, and I say you can't either. We don't even have the proto-2119 lanuage here that we see in RFC 1123, so we can't tell whether the "The labels must follow" in the last paragraph is a protocol restriction or a consequence of following the "prudent user" advice that immediately preceeds it. It might be policy, and it might not be. One way to figure out whether this is "mere" policy or whether it is in fact protocol is to ask people. It turns out, however, that different people have responded differently to this. Some people have responded by putting eight-bit labels in the public DNS. I claim, therefore, that regardless of whether the rule in RFC 1123 is or is not clearly policy, we should document that we explicitly permit, as a matter of protocol, certain characters in the top level. The draft as written carefully points out that there are lots of things that are policy and not the domain of the IETF. This just states that, in case anyone thinks there is a problem with top level IDNA2008 labels, there isn't. And I say again (for the last time, since I think I'm just repeating myself now), if one thinks that the restriction in 1123 is clearly not a protocol restriction, then there is nothing to say and we can be quiet. A -- Andrew Sullivan a...@shinkuro.com Shinkuro, Inc. _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop